WO2011161215A1 - Réacteur horizontal, haute pression à mélamine - Google Patents

Réacteur horizontal, haute pression à mélamine Download PDF

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Publication number
WO2011161215A1
WO2011161215A1 PCT/EP2011/060553 EP2011060553W WO2011161215A1 WO 2011161215 A1 WO2011161215 A1 WO 2011161215A1 EP 2011060553 W EP2011060553 W EP 2011060553W WO 2011161215 A1 WO2011161215 A1 WO 2011161215A1
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WO
WIPO (PCT)
Prior art keywords
reactor
compartment
melamine
dome
melt
Prior art date
Application number
PCT/EP2011/060553
Other languages
English (en)
Inventor
Arne Schadt
Robert Schlesinger
Original Assignee
Borealis Agrolinz Melamine Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Borealis Agrolinz Melamine Gmbh filed Critical Borealis Agrolinz Melamine Gmbh
Priority to EP11736301.0A priority Critical patent/EP2585212B1/fr
Priority to PL11736301T priority patent/PL2585212T3/pl
Priority to CN201180028987.2A priority patent/CN102946990B/zh
Priority to US13/806,157 priority patent/US9024020B2/en
Publication of WO2011161215A1 publication Critical patent/WO2011161215A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J10/00—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor
    • B01J10/005—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor carried out at high temperatures in the presence of a molten material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J10/00—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/0053—Details of the reactor
    • B01J19/006—Baffles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/24—Stationary reactors without moving elements inside
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
    • B01J3/04—Pressure vessels, e.g. autoclaves
    • B01J3/042—Pressure vessels, e.g. autoclaves in the form of a tube
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J4/00—Feed or outlet devices; Feed or outlet control devices
    • B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
    • B01J4/002—Nozzle-type elements
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
    • C07D251/40—Nitrogen atoms
    • C07D251/54—Three nitrogen atoms
    • C07D251/56—Preparation of melamine
    • C07D251/60—Preparation of melamine from urea or from carbon dioxide and ammonia
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D251/00—Heterocyclic compounds containing 1,3,5-triazine rings
    • C07D251/02—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings
    • C07D251/12—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members
    • C07D251/26—Heterocyclic compounds containing 1,3,5-triazine rings not condensed with other rings having three double bonds between ring members or between ring members and non-ring members with only hetero atoms directly attached to ring carbon atoms
    • C07D251/40—Nitrogen atoms
    • C07D251/54—Three nitrogen atoms
    • C07D251/62—Purification of melamine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00049—Controlling or regulating processes
    • B01J2219/00051—Controlling the temperature
    • B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
    • B01J2219/00076—Controlling the temperature by indirect heating or cooling employing heat exchange fluids with heat exchange elements inside the reactor
    • B01J2219/00083—Coils
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00049—Controlling or regulating processes
    • B01J2219/00051—Controlling the temperature
    • B01J2219/00074—Controlling the temperature by indirect heating or cooling employing heat exchange fluids
    • B01J2219/00087—Controlling the temperature by indirect heating or cooling employing heat exchange fluids with heat exchange elements outside the reactor
    • B01J2219/00101—Reflux columns
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/00761—Details of the reactor
    • B01J2219/00763—Baffles
    • B01J2219/00765—Baffles attached to the reactor wall
    • B01J2219/00768—Baffles attached to the reactor wall vertical
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/18—Details relating to the spatial orientation of the reactor
    • B01J2219/182—Details relating to the spatial orientation of the reactor horizontal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J2219/19—Details relating to the geometry of the reactor
    • B01J2219/194—Details relating to the geometry of the reactor round
    • B01J2219/1941—Details relating to the geometry of the reactor round circular or disk-shaped
    • B01J2219/1943—Details relating to the geometry of the reactor round circular or disk-shaped cylindrical

Definitions

  • the present invention relates to a melamine reactor according to claim 1 and a process for obtaining melamine according to claim 13.
  • Melamine is usually obtained from urea in the presence of ammonia according to
  • the industrial processes for melamine synthesis are mainly classified into a catalytic process at low pressures below 1 MPa and non-catalytic processes at high-pressures above 5 MPa (see Ullmann's Encyclopedia of Industrial Chemistry, 6th edition, Vol. 21 , p. 205 ff).
  • the high-pressure melamine process starts out from pressurized molten urea at temperatures between 135 and ⁇ ⁇ ' ⁇ and is carried out in a pressure range between 5 and 20 MPa and a temperature range of 370 to 430 ⁇ €.
  • the high pressure part comprises basically three sections, in which the following process steps are carried out:
  • the conversion of urea to melamine is carried out in a synthesis reactor with heating bundles.
  • the obtained raw melamine melt is then transferred to a second reactor or stripping reactor in which the dissolved gases, in particular C0 2 , are removed from the melamine melt by introducing gaseous ammonia in counter current, and where the melamine melt is allowed to reside for a certain time (Aging).
  • the offgases generated during the melamine synthesis reaction are usually removed in the upper part of the melamine reactor and then transferred to the scrubber.
  • the raw melamine melt is introduced in the second reactor where ammonia gas is introduced in counter current for removing C0 2 from the melt which is also transferred to the scrubber.
  • the melamine melt is allowed to reside for a certain time (Aging).
  • liquid or gaseous ammonia can be introduced to the reaction melt.
  • the ammonia is fed through a suitable inlet, in particular through a distributor, injector or nozzle.
  • the offgas is removed from the stripper and sent to a scrubber where the offgas is cooled, melamine present in the offgas is separated from the offgas, and in counter current the urea melt is preheated.
  • the urea melt comprises fresh urea or circulating urea which is kept in circulation by a circulation pump. This urea circulation pump serves also for feeding the preheated urea melt to the high pressure melamine reactor.
  • the excess heat in the scrubber is removed by an external heat exchanger. All in all, a conventional high pressure part of a melamine plant consists of approximate 5 different main pieces of equipment, in particular synthesis reactor, stripper, scrubber, heat exchanger and circulation pump, which are connected by a number of pipes.
  • this construction requires a number of different bulk materials like pipes including the proper insulation, and intensive heat tracing, valves, steel structures and more.
  • Such a complex system of reactors, pipelines and valves is however difficult to operate and to maintain.
  • This high-pressure melamine reactor comprises three sections separated from each other by means of diaphragms: a top sector serving as washing or scrubbing sector, a central sector serving as stripping or separation sector, and a bottom sector serving as synthesis reactor. Each sector communicates with the other two sectors through pipelines.
  • this reactor still requires a number of different equipment like diaphragms, pipelines and valves making it vulnerable to corrosion by the processing fluids or melts and causing high costs.
  • the present high-pressure melamine reactor comprises at least one horizontal reactor body having a bottom and a top side with at least one dome integrally formed on the top side of the reactor body.
  • the at least one horizontal reactor body comprises at least two compartments, which are separated by at least one baffle, in particular an overflow baffle.
  • the dome is arranged or located above one of the two compartments, more precisely above the compartment which serves as melamine synthesis unit.
  • the reactor is separated in two compartments which are in liquid communication with each other.
  • One of the two compartments forms thereby an equivalent to the first reactor, e.g. melamine synthesis reactor, and the second compartment of the two forms an equivalent to the second reactor, e.g. stripper.
  • the at least first compartment serves as a melamine synthesis unit and the second compartment serves as a stripping unit.
  • the at least one dome serves as a scrubber unit including a heat exchanger.
  • the reactor according to the invention enables thus the conduction of three reaction steps, e.g. melamine synthesis, stripping the melamine melt from any excess of gas, in particular C0 2 , and scrubbing the offgases in one piece of equipment instead in five conventionally used pieces.
  • the present reactor allows for a narrow and complex design, less equipment and hence less bulk material. Due to the horizontal arrangement of the reactor the overall height is reduced.
  • a high pressure urea circulation pump is no longer required since the urea melt flows into the reactor compartment by gravity.
  • the larger interface in the stripper compartment allows an improved mixing between melamine melt and the introduced ammonia.
  • Overall the present reactor requires less investment costs and less operation costs compared to conventional operated high pressure parts of a melamine plant.
  • the inventive reactor design allows for a real two-step reaction wherein the residence time for each of the reaction steps can easily be adjusted by means of the fluid level in the respective compartment. Any back mixing is avoided so that the quantity of non- reacted compounds is extremely reduced in the reaction mixture.
  • the dimensions, more precisely the diameter of the dome corresponds at least to the dimension or diameter of the compartment serving as melamine synthesis unit.
  • the dimensions of the dome such width or diameter are the same or less than the dimensions as width or diameter of the melamine synthesis compartment. This means that the dome is arranged solely above one compartment and thus covers fully or partially only the one compartment and does not extend over more than the one compartment.
  • the overall length of the horizontal reactor can be between 5 and 15 m, preferably between 7 m and 13 m, in particular preferably between 9 and 1 1 m.
  • the dome may comprise at least one inlet for urea melt, at least one outlet for off gases and at least one heat exchanger.
  • the dome is preferably located above the area of the first compartment of the body reactor used for melamine synthesis so that the offgases released during the reaction of urea to melamine move continuously upwards into the dome and are being scrubbed and freed there from melamine in counter flow by the incoming urea melt. The offgases are thereby washed, cooled and finally released and reused for instance in urea production.
  • the urea melt enters the dome preferably with a temperature between 135 and 250 °C.
  • the interface between the reactor body and the dome can be designed such that it is partially or completely open e.g. the interface can be either covered by a bubble cap tray, a sieve tray or alike or it can be completely free of any cover. In any case, a continuous stream of urea melt from the dome into the first compartment and a continuous stream of offgases from the first compartment into the dome have to be guaranteed.
  • the dome comprises preferably a cylindrical top.
  • the cross section of the dome has to be specified with respect to the gas velocity.
  • the gas velocity in turn should be low enough to allow settling of the urea droplets and/or the melamine carryover from the offgas stream.
  • the dome can have a diameter between 1 m and 5 m, preferably between 1 m and 3 m, in particular preferably between 1 m and 2 m.
  • the height of the dome can be between 1 and 10 m, preferably 3 and 8 m, in particular preferably between 4 and 6 m.
  • At least one of the two compartments, preferably the compartment used for melamine synthesis, of the horizontal reactor body comprises at least one heating element.
  • the heating element can be heated by molten salt, thermal oil or alike.
  • Said compartment can also comprise an inlet, like an injector or a nozzle, for feeding additional compounds, in particular ammonia into the synthesis section.
  • the pressure in the synthesis area is between 5 and 20 MPa, preferably between 8 and 15 MPa in dependence of the reactor temperature.
  • the temperature in the synthesis compartment or part of the reactor is - depending on the applied pressure - between 330 and 450 °C, preferably between 330 and 400 ⁇ €, in particular preferably between 330 and 380 °C. In this respect it is important that the temperature at the prevailing pressure is high enough for keeping the melamine melt in the molten state in order to avoid blocking.
  • the connecting area between both, bubble cap trays, sieve trays or similiar structures are preferably arranged for improving the separation effect of the offgases and preventing melamine melt entering the dome zone.
  • the connecting area between both, bubble cap trays, sieve trays or similiar structures are preferably arranged for improving the separation effect of the offgases and preventing melamine melt entering the dome zone.
  • At least a second of the two compartments preferably the compartment used as a stripper unit, comprises at least one inlet for gaseous ammonia and at least one outlet for melamine melt.
  • the ammonia gas should be fed with a pressure which is somewhat higher than the pressure in the stripper compartment.
  • the flow rate of the ammonia gas should be high enough to minimise C0 2 solubility in the melamine melt.
  • the temperature and pressure in the stripping compartment are basically the same as in the synthesis compartment.
  • the ammonia inlet comprises preferably multiple nozzles, which are arranged along the lower side of the body reactor in the lower part of the stripping compartment.
  • the ammonia inlet may also be constructed in form of a distribution plate having openings or alike.
  • the nozzles or openings are dimensioned in such a manner that a fine distribution of the ammonia gas in the melamine melt is guaranteed. This in turn provides an intensive and homogenous mixing and therefore enables good and almost quantitative removal of offgases.
  • the at least two compartments of the reactor body are separated by the at least one baffle such that the synthesis compartment can comprise at least one half, preferably two thirds of the horizontal reactor and the stripping compartment can comprise up to one half, preferably one third of the volume of the reactor.
  • both compartments have almost the same volume.
  • the volume of the horizontal reactor and thus the volume of the two compartments have to be specified according to the residence time that is necessary to complete the reactions.
  • the height of the at least one baffle is at least one third, preferably between two thirds and three quarters of the height of the horizontal reactor.
  • the baffle is preferably designed as an overflow baffle. It is also conceivable that more than one baffle is placed in the reactor whereby the multiple baffles can be of different heights, respectively.
  • the baffle is arranged is the reactor such that the synthesis compartment comprises about two thirds of the horizontal reactor and the stripping compartment about one third of the reactor volume.
  • the dimensions of the reactor depend on the overall plant capacity and on the operating pressure which should be between 5 and 20 MPa.
  • the individual compartments have to be designed such that volumes, exchange surface, residence times of the fluid, the flow rates of the fluids, the maximum pressure drops for the reactor operation are easily adapted and guarantee the optimal performance of the reactor.
  • the object of the present invention is also solved by a process according to claim 13.
  • the process for obtaining melamine from urea at high pressure in a reactor comprises the steps of feeding liquid urea into the at least one dome of the reactor, heating the liquid urea in the at least one first compartment of the reactor, separating the offgases from thus obtained melamine melt by releasing the offgases through the dome, transferring the melamine melt obtained in the at least one first compartment over the at least one baffle into the at least one second compartment of the reactor, feeding gaseous ammonia into the at least one second compartment of the reactor, and releasing the thus stripped melamine melt from the at least one second compartment.
  • the melamine flow through the reactor is driven by the pressure difference between the reactor and the downstream equipment.
  • the dome operating as a scrubber compartment performs the following functions: the fed urea melt is pre-heated, and the offgases from the melamine synthesis are cooled and washed such that any melamine present in the offgases is removed.
  • the urea melt enriched with melamine and a certain amount of the offgas is passed by gravity into the first compartment of the reactor where melamine synthesis occurs.
  • the urea melt enters the dome with a temperature between 135 and 160°C.
  • the offgases ascending from the synthesis and the stripping compartment heat the urea melt to a temperature between the inlet temperature and the reaction temperature, for instance to a temperature between 200 and 250 ' ⁇ .
  • the ascending offgases are cooled down and are discharged with a temperature above 200 °C.
  • the temperature difference of the gas and liquid is small due to the intensive contact of gas and liquid in the packing.
  • a heat exchanger is used to adjust the gas and liquid temperature. The excess heat serves for steam generation in a heat exchanger.
  • the cooled offgases are finally released on the top of the dome through an outlet, for instance a pressure control valve.
  • the urea melt descends through the dome into the first compartment of the reactor, where it is heated to a reaction temperature between 330 and 450 °C, preferably between 330 and 400 °C, in particular preferably between 330 and 380 °C.
  • the temperature depends on the applied pressure which is between 5 and 20 MPa, preferably between 8 and 15 MPa.
  • Urea is converted to melamine in this first compartment.
  • the heat required is supplied by a heating bundle which is preferably operated with molten salt or thermal oil.
  • the offgas generated in the course of the reaction ascend through the reaction mixture into the dome whereby causing high turbulence of the melamine melt and thus at least a partial circulation of the melamine melt.
  • the temperature gradient between the heating bundle and the melamine melt contribute to the natural recirculation of the reaction melt in the synthesis compartment.
  • the offgases in particular NH 3 and C0 2 formed during the melamine reaction, are separated in a continuous manner from the reaction melt. As described above, the offgases ascend into the dome, are cooled there and released through at least one outlet, for instance a pressure control valve. A continuous offgas-stream into the dome is guaranteed due to the upward flow of the offgases, whilst the liquid urea melt flows downwards.
  • the melamine melt flows over the at least one baffle into the second compartment e.g. stripping compartment of the reactor.
  • This second compartment which serves as a stripping compartment may fulfil at least two functions.
  • the gaseous products, in particular NH 3 and C0 2 are removed from the melamine melt and the melamine melt is allowed to reside (Aging).
  • Aging-phase melamine resides in the second compartment of the reactor in the presence of an excess of ammonia to allow partial conversion of deammonisation products into melamine.
  • gaseous ammonia is fed into the second compartment.
  • the ammonia is fed through a suitable inlet, in particular through a distributor, injector or nozzle.
  • a suitable inlet in particular through a distributor, injector or nozzle.
  • the gaseous ammonia is preheated to a temperature above 330 °C.
  • the limiting factor for temperature of ammonia gas is the risk of solidification of the melamine melt, e.g. the ammonia temperature must be high enough so that the melamine does not solidify and does not block the nozzles.
  • the stripped melamine melt may finally leave the reactor through at least one suitable outlet, in particular a pressure control valve, for further work up.
  • Fig. 1 a scheme of a conventional high-pressure melamine synthesis reactor according to prior art
  • Fig. 2 a schematic view of a high-pressure melamine synthesis reactor according to an embodiment of the invention.
  • FIG. 1 shows a scheme of a conventional high-pressure part of a melamine synthesis plant.
  • the high-pressure part consists basically of a synthesis reactor 10 as a first reactor, a stripping reactor 1 1 as a second reactor and a scrubber 12.
  • the conversion of urea to melamine is carried out in the synthesis reactor 10 which is equipped with heating bundles.
  • the obtained raw melamine melt is then transferred to the second reactor or stripping reactor 1 1 in which the residual gases are removed from the melamine melt by introducing gaseous ammonia in counter current, and where the melamine melt is allowed to reside for a certain time (Aging).
  • the offgases are removed from the stripper 1 1 and sent to the scrubber 12 where the offgases are cooled and the urea melt is preheated.
  • the urea melt comprises fresh urea or circulating urea which is kept in circulation by a circulation pump 13.
  • the excess heat in the scrubber is removed by an external heat exchanger 14.
  • FIG. 2 shows a high-pressure reactor 1 according to the invention.
  • the reactor 1 comprises essentially a dome 2, a melamine synthesis compartment 3 and a stripping compartment 4, the two compartments separated by an overflow baffle 5.
  • Example 1 shows a high-pressure reactor 1 according to the invention.
  • the reactor 1 comprises essentially a dome 2, a melamine synthesis compartment 3 and a stripping compartment 4, the two compartments separated by an overflow baffle 5.
  • a horizontal reactor that produces 50,000 tons per year of melamine has the following approximate dimensions.
  • the reactor has a diameter of 2 m and a length of 10 m.
  • the dome has a diameter of 1 .80 m and a height of 5 m.
  • the baffle has a height of 1 .50 m and separates the reactor at 7.50 m so that the volume of the synthesis compartment comprises of three quarters of the total reactor volume.
  • Urea enters the dome of the reactor at 150°C and is preheated by the offgas, and melamine impurities in the offgas are washed out. The excess heat is removed by a heat exchanger that generates steam. The purified offgas is discharged from the reactor with a temperature of approx. 200 °C.
  • the temperature in the reactor is 370 ⁇ and the pressure is 10 MPa.
  • urea reacts to a melamine melt.
  • the heat of reaction is supplied by a heating bundle that operates with molten salt.
  • Offgas is generated at the heating bundle and enhances turbulence and heat transfer of the heating bundle to the melamine melt.
  • the offgas ascends to the surface of the melamine melt and is liberated there.
  • the synthesis compartment When the synthesis compartment is full with molten melamine, it flows over the baffle to the stripping compartment. Ammonia at 400 ⁇ and 10.5 MPa is fed to the stripping compartment and strips dissolved C0 2 from the melamine melt.
  • the level in the stripping compartment is controlled by a valve at the outlet of the reactor that adjusts the flow of the melamine melt.
  • the thus obtained melamine has a purity of at least 99,8 %.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)

Abstract

La présente invention concerne un réacteur à mélamine haute pression caractérisé par au moins un corps de réacteur horizontal présentant une face inférieure et une face supérieure, doté d'au moins un dôme formé intégralement sur la face supérieure du corps de réacteur. Ledit au moins un corps de réacteur horizontal comprend au moins deux compartiments séparés par au moins un déflecteur, en particulier un déflecteur à surverse. L'invention concerne en outre un procédé de production de mélamine utilisant le réacteur.
PCT/EP2011/060553 2010-06-24 2011-06-23 Réacteur horizontal, haute pression à mélamine WO2011161215A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP11736301.0A EP2585212B1 (fr) 2010-06-24 2011-06-23 Réacteur horizontal, haute pression à mélamine et procédé
PL11736301T PL2585212T3 (pl) 2010-06-24 2011-06-23 Poziomy wysokociśnieniowy reaktor melaminy i sposób
CN201180028987.2A CN102946990B (zh) 2010-06-24 2011-06-23 卧式高压三聚氰胺反应器
US13/806,157 US9024020B2 (en) 2010-06-24 2011-06-23 Horizontal high-pressure melamine reactor

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP10167186.5 2010-06-24
EP10167186A EP2399669A1 (fr) 2010-06-24 2010-06-24 Réacteur de mélamine horizontal haute pression

Publications (1)

Publication Number Publication Date
WO2011161215A1 true WO2011161215A1 (fr) 2011-12-29

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PCT/EP2011/060553 WO2011161215A1 (fr) 2010-06-24 2011-06-23 Réacteur horizontal, haute pression à mélamine

Country Status (5)

Country Link
US (1) US9024020B2 (fr)
EP (2) EP2399669A1 (fr)
CN (1) CN102946990B (fr)
PL (1) PL2585212T3 (fr)
WO (1) WO2011161215A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2907567A1 (fr) 2014-02-18 2015-08-19 Casale Sa Réacteur combiné pour la synthèse haute pression de mélamine
EP3075725A1 (fr) 2015-03-30 2016-10-05 Casale SA Sonication dans un processus de synthèse de l'urée ou la mélamine

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102631879A (zh) * 2012-05-07 2012-08-15 中国电力工程顾问集团华北电力设计院工程有限公司 烟气脱硝稳流式尿素水解制氨反应器
CN109621842B (zh) * 2018-12-27 2024-04-09 中国船舶重工集团公司第七一0研究所 一种用于卧式压力釜的水平启闭装置
EP4342016A1 (fr) 2021-05-19 2024-03-27 Saft Ensemble de recouvrement pour cellule électrochimique, cellule électrochimique et batterie correspondantes
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EP2907567A1 (fr) 2014-02-18 2015-08-19 Casale Sa Réacteur combiné pour la synthèse haute pression de mélamine
US9938247B2 (en) 2014-02-18 2018-04-10 Casale Sa Combined reactor for high-pressure synthesis of melamine
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EP3075725A1 (fr) 2015-03-30 2016-10-05 Casale SA Sonication dans un processus de synthèse de l'urée ou la mélamine
WO2016156015A1 (fr) 2015-03-30 2016-10-06 Casale Sa Sonification dans un procédé de synthèse d'urée ou de mélamine
US10507451B2 (en) 2015-03-30 2019-12-17 Casale Sa Sonication in a urea or melamine synthesis process

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EP2399669A1 (fr) 2011-12-28
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US9024020B2 (en) 2015-05-05
US20130172555A1 (en) 2013-07-04
EP2585212A1 (fr) 2013-05-01
CN102946990A (zh) 2013-02-27
EP2585212B1 (fr) 2014-10-15

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